Picture-projecting device.



C. F. JENKINS. PICTURE PROJBOTING DEVICE. APPLIUATION FILED Mmmo. 191s.

1 @9O,622. Patented Mar.17,1914.

muewto'a PIGTURE-PBOJECTING DEVICE.

Specification 0 Application filed March 2 To all whom. it may concern I Be it known that 1, CHARLES FRANCIS Junnms, a citizen of the United States, residlng at Washington, District of Columbia, have invented certain new and useful lmprovements in Picture-Projecting Devices, of which the following is a specification, reference being; had therein to the accompanying drawing.

This invention relates especially to devices which produce light and project it through a film or plate to show motion or other pic- 'tures, all the parts being carried by a casing from which they may be readily remover, and its principal objects are to provide a light, convenient and compact apparatus which delivers light uniformly with less than the usual heat and which may be operated even bychildrcn without serious danger'of injury to themselves or others.

In the accompanying drawings, Figure 1 is a plan view of the apparatus. Fig. 2 is a partial section on the line 2-2 of Fig. 3. Fig. 3 is a section on the line 3--3 Fig. 2.

.ln these figures, A represents a casing consisting of a rectangular sheet metal box, having a support A, open at one end and closed at the other by an upwardly removablesliding sheet metal plate A. To this plate are secured binding posts B, B, a sight glass B, and holders C C adapted to carry 4 at right angles two small slidingly adjusta'ble carbons D, D projecting within the body of the casing. At the opposite end the casing is provided with a rectangular lens frame E having ways E in which ordinary picture bearing plates may rest when stationary pictures are to be projected, and

in this frame separated circular lens members ii are held at their rpxatlrantul points,

leaving open air spaces s, at the four angles of the frame which tin the casing but is readily withdrawn bodily therefrom. in the central portion of the casing is a similarly removable tubular drum having at each end rectangular flange members H which fit the interior of the casing and are connccted by an open sheet metal cylinder or drum body H. Upon the body H, which bears insulating material H is spirally wound a wire coil I forming a rheostat to control the current through the carbons, the holders of which are connected to the ends of the coil by Wires J, J, respectively. Below the arc space the casing is provided with a series of small apertures K and above it is 1 Letters Patent.

0, 1913. Serial No. 755,750.

The casing is also perforated above and below the rheostat, so that cooling air may pass around the drum.

The carbons are small and the lens llit'lll bars are large and naturally, they absorb much heat from the beam passing through them. Air, however, constantly passes somewhat rapidly around them, through the hollow drum, absorbing heat from that also, and thence through thfefhood above the arc to the open ,air. The lens members never become highly heated and the heat which they givenp to the air bears a direct ratio to their own temperature, the practical result. being that the projected beam of light is never dangerously hot, and a properly arranged film can nwcr be ignited thereby. it is also to be observed that the rheostat occupies space not otherwise utilized and thus adds nothing to the space occupied by the apparatus, and further that its heating is not material to the operator or others,'for contact with it is prevented. The light is produced by current not in any case especially dangerous, and, lilo he rheostat, the arc 'annot he accidentally reached by any- 1s to connect the usual ii-icandescent light wires to the binding posts and strike the are by adjusting the carbons.

Practically, all danger from fires iseliminated as well asall danger of personal injury, and \vil'hal the apparatus is'extremely simple, light, and inexpensive, and at the same time unusually convenient in transportation and use.

llhal I claim is:

'1. ln apparatus of the class described, the combination with an electric light, a projecting lens, a rheostat in series with the light, and a casing inclosing the light, lens and rheoslat, the partsbemg arranged to permit Cooling" air to pass freely into the casing, upwardly through the interior chamber, and out of the casing.

- 2. In apparatus of the class described.'the combination with a casing or box, of a rear electric light, a front projecting lensand an intermediate rheostat in series with the light, all inclosed by the casing, said casing having apertures to permit cooling air to pass freely upward through the rear end of air entering around the lens.

The combination with 'a sheet metal a larger opening L protected by a hood L."

thing. All that is necessary for installation the box and to allow the escape of cooling Patented Mar. 1'7, 1914i.

casing having llUdI' one end an inclosed externally regulated are light and provided ivith openings holow and above the light for the entrance and escape of cooling air, of a lens inelosed in thmensing near iLs opposite end and held hy devices allowing air to pass freely over iis edge and face surfaces, and. :1 rhuostut also inclosed in the casing and a1- rvngeiil 10 be cooled by air currents which have passed over the lens surfaces.

4-. The co1nbim1ti .)n with :1 sheet metal casing, of 1111 are light mounted in one end portion of Lilo casing, a prcqectmg lens mounted in the opposite end of the casing in l a frame permitting cooling air to pass freely over its edges at Various points, and a. t\l bulnr rheosl'ut in the path of ooolin air, passing ruarwuul from the lens, 11ml outside the path of light passing to the lens, said casing having perforations above and below said light and rheostzit to allow free passage of cooling air.

In testimony whereof I affix in presence of two witnesses.

CHARLES FRANCIS JENKIN S,

Witnesses;

J, R.- \Vm'm, JAMES L. CRAWFORD.

my signature 

